BOOK REVIEW : Penetrating to Core of Humanity, Science : SAVING ST. GERM by Carol Muske Dukes ; Viking $21, 264 pages

Prize-winning Los Angeles poet Carol Muske Dukes amused readers four years ago with her witty first novel, “Dear Digby.”

That book featured a letters editor at a feminist magazine that bore a close resemblance to Ms., and the story bounced back and forth between the string of wacko letters she published--and answered hilariously--and her demanding personal life, strained by a rocky marriage.

Now Dukes is back with a riveting new novel that probes much of the same material. This time she has her story more firmly in hand, and she penetrates deeper into the dark wood of a woman’s marriage-and-career struggle, now complicated, and enormously enhanced, by the presence of a bright but maladjusted young daughter.

Dukes’ heroine in “Saving St. Germ,” Esme Charbonneau, is a scattered, intense science professor who relaxes by imagining the Tinkertoy-like atomic shapes of molecules. Charbonneau holds a teaching and research appointment at the “University of Greater California,” a thinly disguised USC.

Her husband, Jay, is a technical director for a television production company in Hollywood. Her kindergarten-age daughter, Ollie, whom Jay named “Olivia” after a movie star Charbonneau had never heard of, compulsively spins in circles, wears a cardboard television set over her head and speaks in riddles that only her mother can decipher.

*

The story opens with the couple immersed in their separate careers. Charbonneau, who tells the story in perfect-pitch first person, is teaching difficult and dreary organic chemistry to snotty undergraduates, having allowed her own research to languish after Ollie was born.

Husband Jay is completely absorbed at work in making sure the right cameras are on the right sitcom actors at the right times. When he’s off duty, he devotes himself just as single-mindedly to telling deliberately bad jokes on the stages of obscure comedy clubs. Little Ollie, meanwhile, occupies herself with her mysterious activities, sometimes tagging along with Charbonneau.

But now Ollie has reached school age, and her father thinks her weirdness can no longer be ignored. Should the girl be allowed to develop along her own eccentric but, in her mother’s opinion, intellectually promising lines, or should she be forced into normality? The parents start a tug-of-war.

The dramatic spring tightens when Jesse, an old lover of Charbonneau, reappears. A medical doctor, he represents to the professor, besides a great roll in the hay, devotion to human life as opposed to her own remoteness and scientific abstraction.

The book’s title comes from an argument they have.

The handsome, basketball-playing MD says, “You know what I like about medicine? What every decent doc likes. Being right there in the swamp: the emergency room, triage. No, really. Don’t laugh, I do, I’m in the ball game. You people, you blender jockeys, sit around splicing and snipping and staining slides, looking at squiggles in microscopes and deducing profundities. Looking for St. Germ. Saving St. Germ. Some tiny little organism, some protein sequence, that’s going to change the quality of human life, but only intellectually, only as a model for thought.”

*

Rather than be converted to Jesse’s devotion to human beings, Charbonneau charges with new energy in exactly the opposite direction.

Pursuing a grand, and completely mathematical, “Theory of Everything”--a single scientific explanation of all the workings of the universe, from the cosmic Big Bang down to the structure of the smallest molecules of life--she neglects her family, her classroom and her laboratory.

As Charbonneau nears solving the equations in her Theory of Everything, her life spins out of control. Her dean relieves her of her teaching appointment and her husband leaves her, taking Ollie.

Charbonneau plunges through the bottom of her life, a truly Dostoevskyan figure in her anguish. And it is not giving away too much to say that her extremity of suffering is redeemed by a commensurately powerful epiphany.

“Saving St. Germ” isn’t perfect. Charbonneau’s unrelieved meanness, clever though it be, takes a while to get used to. Her sweaty Italian doctor-lover arrives straight from Central Casting. And some important plot strands are left loose at the end. Nonetheless, the story, and particularly the final scene, is mesmerizing.